


A four letter word

by Cherubuni



Category: BBC Sherlock, Sherlock Holmes - fandom
Genre: Crush, Fluff, Kinda?, M/M, eventually sherlock is too :3c, i have so many feelings for these boys, john is an adorable dad, sherlock doesnt know how to deal with having a crush, slowburn, this takes place after s4
Language: English
Status: Completed
Published: 2019-03-14
Updated: 2019-03-14
Packaged: 2019-11-18 03:17:40
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 4,075
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18112166
Author URL: https://archiveofourown.org/users/Cherubuni/pseuds/Cherubuni
Summary: Sherlock understands complex mathematics, chemistry, physics. He can solve a crime by spending five minutes in a room. He’s brilliant. But there’s just one thing he really doesn’t understand...





	1. Chemical reaction

Sherlock screwed his eyes shut, concentrating hard. Things had been different since Mary died. Very different. He was feeling all kinds of things that a well oiled machine should never feel, like guilt, and regret, and... something else. Something to do with John.  
It had always been there, of course. From the moment John had first saved his life, Sherlock felt an attachment to him that he couldn’t quite explain.  
It’s why he was so frightened when Moriarty used John as a live bomb, so distraught that he might really never see him again after the Magnussen case. It’s why he left John’s wedding early. 

“I’m back” John announced, opening the door to the flat and setting down he bags of shopping he was carrying. “You alright?” He glanced over at Sherlock, who had only just opened his eyes, and was still sat in his thinking position.  
“Mm. Yes.” Sherlock responded, before glancing down at the shopping bags. “Did you bring what I asked for?”  
“What? Human eyes?” John scoffed, carrying the bags into the kitchen and beginning to unload them. “No way.”  
“It was worth a shot” Sherlock mused, before standing up and stretching.  
“Fancy going out tonight? I’ll pay.”  
John turned, raising an eyebrow. “Where’s this suddenly come from?”  
Sherlock shrugged his shoulders. “Just feel like it.”  
“You never just ‘feel’ like it. Is it for a case?” John frowned.  
“No, not for a case.” He flicked his gaze to the ground for a split second, before looking back at John. “I understand if you’re busy, though I have checked your schedule and you’re not”  
“Checked my-“ John cut himself off, sighing heavily. “Alright Sherlock, sure. Could do with a break.”  
John met Sherlock’s gaze and smiled.

It was just a little Chinese place a few streets away. Nothing too extraordinary or fancy, Sherlock just felt the impulse to do something nice for John. Sherlock shuddered slightly as they sat down. ‘Impulse.’ Going to a restaurant, it was so...ordinary, and yet with John it felt completely right.  
“Sherlock?”  
Sherlock snapped out of his thoughts. “Yes?”  
“I asked if you were alright” John smiled slightly. He knew Sherlock could get lost in thought sometimes. Most likely he was busy deducting the ages, occupations and insecurities of everyone in the restaurant, but he wanted to keep Sherlock in the moment.  
“I’m perfect” Sherlock picked the menu up, and gave John a smile. “Shall we order?” 

The dinner went well, with John doing most of the talking and Sherlock picking at his plate. He didn’t really like eating in front of other people, and John knew this, so he didn’t push it. He knew Sherlock would probably eat more when they got home.  
“You know,” John started, taking another bite of his dumpling. “We should do this more often. Haven’t felt this normal in ages.”  
“Don’t worry, the restaurant owner is part of an underground smuggling ring. We’re not boring yet.” Sherlock retorted, smirking a little. John smiled broadly, laughing a little and looking around.  
“I bloody hope you’re joking. I can’t chase criminals on a full stomach” he grinned back at Sherlock, and Sherlock’s heart nearly stopped. John’s smile was sunshine incarnate. He loved how human he was.  
If Sherlock’s heart was frosty and dead, John’s smile thawed it out.  
He held onto that feeling all the way home. 

Back at 221b, John had just come out of the shower, and was getting ready for bed. Sherlock, as predicted, was eating ice cream directly from the tub and watching some crappy telly. He turned when he heard John leaving the bathroom, watching his flatmate wander into the living room. As usual after a shower, John was wearing his white and blue striped bathrobe, with his hair all wet and spiky.  
“I’m off to bed now. See you in the morning?” John stretched, running a hand through his hair.  
“Yes, goodnight John.” Sherlock nodded, before suddenly turning to him. “Wait-” he called after him, setting his bowl of ice cream down.  
“Yeah?” John looked over at Sherlock.  
“John, I need to ask you about something.” Sherlock tapped his fingers together. John knew that sign. It was his thinking twitch. Something was clearly on Sherlock’s mind.  
“Alright, what is it?” John frowned lightly.  
“What is love to you?” Sherlock asked. “Beyond the chemical reaction, I mean. How would you describe love?”  
John raised his eyebrows. “Oh. Uh..not sure I guess. Like, it’s a feeling-“  
“Details, John.”  
“Uh, it’s sort of like...love is like you know how when you find a really good case, right? It’s interesting, and you get all excited about it and do your broody long coat thing and commit to finding out all the details about the case. You like it, and you want everything to do with it. It’s like that, except ideally you stay with the person you love for as long as possible.” John rubbed the back of his neck. “Not a great analogy, I know”  
Sherlock had his eyes closed in thought. John had used an analogy that Sherlock would be able to directly relate to, and still explain how he felt about it in his own words. He didn’t think it was a great analogy, he thought it was a perfect one.  
Of course, Sherlock was too proud to say that aloud.  
“Thank you” Sherlock opened his eyes. “That was all I needed.”  
John nodded. “Why did you want to know?”  
Sherlock was silent for a moment. “Case.”  
“Really?”  
“Yes” Sherlock sprung from his chair, and moved to usher John out of the door and up the stairs.  
“Now off to bed with you, you’re very tired, ordinary people like you need lots of sleep for your ordinary brains, etcetera,” he flapped his hands at John, before closing the door on him.  
John stood in silence and utter confusion at the base of the stairs. “Some case, huh?” He muttered to himself, before smiling slightly at climbing the stairs to his bedroom.

Back in the living room, Sherlock was pacing. Yes, this was a case alright. John Watson was by far the most difficult case he had yet to solve. Sighing, he sat down in his chair again and rubbed his forehead. What was wrong with him? John made him /feel/ things. He was Sherlock Holmes. He didn’t have feelings. Right?  
Letting out an exasperated sigh, he muted the volume on the tv and went to go and get some more ice cream. It was going to be a long night.


	2. Comfort

**Summary for the Chapter:**

> Sherlock has a breakdown. John helps him deal with it.

John lay awake in bed, tossing and turning, unable to sleep. Sherlock didn’t know, but John had barely slept since Mary died. She haunted him like a ghost. Between Mary and the bloody war, John was in a bad way. However, despite the person he married being gone, he didn’t feel entirely alone. He had Rosie, of course, his beloved daughter who was staying with Molly for a few days so John could get some rest after the ordeal with Eurus. Yes, John had his daughter, and he also had Sherlock. 

He had Sherlock. 

John rolled over in bed, checking the time and running a hand through his hair. What had tonight been about? First dinner and then…that question about love. Was it guilt talking? John sighed. He didn’t blame Sherlock for Mary’s death, not really. He’d just been in so much pain at the time he needed someone to pour his feelings onto, and Sherlock was the only person he could see fit to. He still felt awful about it, but surely Sherlock was fine now, right? Maybe he should talk to him about it. John rubbed his eyes. He’d do that in the morning. 

Just as he rolled over again to try and settle down to sleep, he heard a clattering coming from the flat downstairs, and was instantly wide awake.   
A door slammed shut, followed by some more clattering, and then silence. And then…something else. Another noise. John knew it was coming directly from their flat, the walls were very thin and he was used to Sherlock making a racket at night, but this time he was worried. His heart was telling him to go check on Sherlock. His heart always won. 

Trudging down the stairs and into the flat, John noticed that the TV was still on, but switched to mute. He turned it off, before looking around. Where was Sherlock?  
“Sherlock?” he called out, wandering through the kitchen and into the hallway. 

That’s when he heard it. 

“Sherlock?” John said again, but softer this time, as he made his way over to the bathroom. The door was locked. He knew that sound all too well. The distinctive noise of someone trying to cover up the sound of their own crying. 

John knocked tentatively on the door. “Sherlock, are you alright?”

There was a brief pause in the noises, and he could hear Sherlock blowing his nose. 

“I’m perfectly alright” came the shaky reply from within. John was a little lost for words. He’d seen Sherlock shaken up a few times before, even witnessed him have a panic attack due to believing he’d seen the hound of the Baskervilles, but crying? That concerned him. Deeply.

“You wanna open the door?” John asked softly, running a hand through his hair. There was a silence before Sherlock replied again.

“I said I’m fine.” 

“Alright.” John sighed. He knew he couldn’t force Sherlock to open the door, but he wasn’t going to leave him like this. “Well I’m going to put the kettle on, and whenever you’re ready to come out, I’ll be here.” John went to busy himself in the kitchen, listening closely to what Sherlock was doing. John was panicked, of course. He wanted- no, he /needed/ to know what was wrong, but right now he needed to be a source of stability for him. It felt like an eternity before the great detective emerged from the   
bathroom, and when he did, he hardly looked great at all. 

Sherlock was shaking, eyes puffy. He could look anywhere but at John, and his chest felt tight. 

“Sherlock” John stood up from the chair he was sat in, making his way quickly over to him. 

“Don’t-” Sherlock started, before taking in a shaky breath and trying again. “Don’t bother yourself with me. Please, I’m fine. There is nothing wrong with me.” Sherlock   
managed to meet John’s gaze. John sighed heavily. 

“No, you’re gonna sit down in your chair and drink the tea I made for you, and you’re gonna tell me what’s wrong.” John stated firmly.

Sherlock gave John a look.

“Please, Sherlock.” John ushered him over to his chair and sat in his own chair opposite him. Sherlock picked up his tea. He was shaking. It spilled a little.   
“I’m sorry” Sherlock’s voice cracked. “I don’t know what’s wrong with me I- I’m being pathetic I’m letting my emotions get the better of me I-“

“Sherlock.” John gently interrupted. “Breathe.”

Sherlock closed his eyes, setting his tea down and rubbing his forehead. John was well aware that Sherlock got very overwhelmed very fast when it came to feelings, because he didn’t know how to process them. Feelings were alien to Sherlock, he said they were too human.   
“Forgive me” Sherlock muttered. “I just…I don’t know what’s wrong with me. Ever since Mary…” he trailed off, looking over at John. He expected to see anger, resentment, even regret in John’s face, but he simply looked calm, and soft. His gaze was so soft, Sherlock could’ve melted.   
“Ever since Mary died saving my life I have been experiencing…feelings. Emotions.” He looked away from John, ashamed. “I don’t know how to deal with guilt. I don’t know to deal with anything at all. I’m lost I…” he looked back at John. “I need you” he said softly.   
John could practically hear his heart breaking. How long had Sherlock been suffering in silence because he didn’t know how to deal with this grief he couldn’t explain?

“Sherlock...” John spoke softly, but words failed him. And when words failed, he did what every human ever does when speech isn’t enough.

He went to hug Sherlock. 

Tightly. 

Sherlock was taken aback by the sudden contact. He absolutely detested physical contact from anyone. Well, anyone but John. He gave in to the hug quite quickly though and carefully, gently, put his arms around John. Sherlock leaned in to the crook of John’s neck, shaking slightly. John rubbed Sherlock’s back. Sherlock was freezing, and John made a mental note to scold him later for not wrapping up warm enough. Eventually, John was the first to pull away. Sherlock could’ve stayed like that all night if it   
was up to him, but he didn’t know how to express that need. 

“Look, I’m gonna go get some sleep. Will you be alright on your own down here?” John asked. Sherlock nodded. 

“Yes.” He was still slightly dazed. John hadn’t ridiculed him, or been angry with him for expressing his feelings. 

“Right. I’m back off to bed then.” John drank the rest of his tea. “Don’t ever feel like you can’t talk to me Sherlock, alright? Because you can. Always. Anytime.” John gave Sherlock one of those heart melting smiles. Sherlock nodded.  
“John?” Sherlock mumbled. “Thank you.” 

“Anything for my best mate.” John replied with another smile, before walking out again, going back upstairs to bed. Sherlock ran his hands through his hair. John saw him as his best friend. Of course they were best friends, so why was it that Sherlock felt…disappointed? Surely there was no logical reason to feel the way he felt, but it had been a strange night. Sherlock was emotionally exhausted.

Making his way to bed, Sherlock only had one thing on his mind. 

John.

**Notes for the Chapter:**

> Hello and thank you for reading the second chapter in 'a four letter word'! I promise next chapter I'll focus on lovey dovey stuff, buut i'm also evil so it might take a little while for that four letter word to be said.... >:3  
> As usual, thank you for supporting my work, and please give me your feedback in the comments below! If there's anything you're dying to see me write, let me know and I might do it! Stay tuned for more <3  
> tumblr: @cherubuni


	3. The little things

**Summary for the Chapter:**

> Rosie is back in 221B, and Sherlock goes to Molly for some advice.

When John woke up the next morning and came downstairs, Sherlock was already out. He’d mentioned something about wanting to do a thing at St Barts, so John wasn’t worried. He rubbed the back of his neck. John had to pick Rosie up later, so he’d have to get some chores done before he did that. He laughed softly. Fatherhood was really hitting him. As John wandered into the kitchen, he saw the kitchen table was in complete disarray. He sighed, somewhat irritated. Sherlock never tidied up after himself. John made himself some tea, and then set about getting on with his morning.

-

“But what about The Woman?” Molly asked, confused. She wasn’t really sure of what Sherlock was asking her. “Everyone thought you loved her”

“I’m not sure what happened between us is what’s conventionally described as ‘love’. She drugged me, I worked out the code to her confidential phone, she got killed by a terrorist group. Not exactly heart stopping.” Sherlock replied in a monotonal way.

“Yeah, but…” Molly sighed. “Sherlock, I don’t think I can help you with this. At the end of the day, you’re the only person who can know if you’re in love or not. It might help if you told me who it is, though” Molly said hopefully. Sherlock sighed. 

“No. I can’t. Not until I’m sure, anyway. It would be like condemning someone before receiving proper evidence. And you know how much I hate misinformation.”  
Sherlock finished his coffee and stood up. “Let me know if you find any interesting bodies, or whatever it is that you do.” Molly gave Sherlock a little look. 

“You know, if it’s John you can just say so.” She muttered. 

“What?” Sherlock frowned at her. 

“Shh, keep your voice down. Rosie’s sleeping.” Molly replied, before sighing. “It’s nothing. I’m sorry I couldn’t help you” Molly smiled slightly. “Good luck with your ‘case’.”  
Sherlock nodded.

“Oh! And tell John Rosie’s ready for him to pick her up whenever.” Molly beamed. Sherlock simply put his coat on and left.

-

Back at 221B, Sherlock was pacing. Was it so obvious that John was the target of his affections that even /Molly/ could deduce it? But how did he know if what he was feeling was really love? All his life he had lived without ever being in touch with his heart, and then John had just come along and melted it. It made no sense. Logically, none of this made sense. He grabbed his notepad and a pen from the kitchen and sat down in his chair. It was time to do some analysis. 

“Sherlock?” An hour later, Sherlock heard John coming up the stairs. “We’re back” John poked his head round the door, beaming at Sherlock, before coming inside. He was carrying Rosie, who looked like she’d just woken up from a nap, and was very unhappy about it. 

“Hello” Sherlock smiled softly. He hated to admit it, but he had a big soft spot for Rosie. Babies weren’t usually his style at all, but John’s baby, however, was a different matter. 

“How was it at Barts?” John asked, setting Rosie down on the sofa and putting his bags to one side.

“Barts?” Sherlock frowned, before realising that he had told John he would be at St Barts today. “Oh! Yes, it was fine” Sherlock glanced down at the notepad in his hands, before slipping it into his pocket. He didn’t want John to see it. 

“Whip any more dead bodies?” John joked, as he helped Rosie out of her coat. Sherlock smiled. 

“You jest, but it is a very effective way of getting results.”

“I’m sure” laughed John, before starting to unload the shopping bags as Rosie bounced gently on the sofa, waving her rattle around. Sherlock watched her. It was hard to imagine he’d been a baby too, once. 

“Crap” John muttered. “Forgot the milk. I’ll have to go back to the shops, are you okay watching Rosie for a minute?” he turned to Sherlock.

“You must be tired. I’ll go.” Sherlock stood up, getting his coat on. 

“You sure?” John frowned. He was still feeling somewhat protective of Sherlock after last night’s episode. He wanted to make sure he was okay. 

“The fresh air will do me some good. I’ll be back soon” Sherlock smiled, before leaving the flat. As he swept out, he failed to notice the notepad falling out of his pocket. John did see it however, and bent to pick it up.

“Sherlock” he called. “You dropped-“ John heard the front door close. “Nevermind” he sighed, and went to sit on the sofa, pulling Rosie onto his lap and gently bouncing her on his knee. Out of curiosity, he glanced at the contents of the notepad, and what he saw made his breath catch in his throat. There were lines of Sherlock’s messy handwriting, and then, at the bottom of the page, underlined several times;

‘Conclusion: I am in love with John Watson’

**Notes for the Chapter:**

> Ooooh cliffhanger >:3c sorry to leave you all hanging like this, but i'll update in a few days time so keep your eyes peeled! Sorry for the short chapter this time, but the next chapter is gonna be a big ooone


	4. L-O-V-E

**Summary for the Chapter:**

> The unspoken four letter word gets spoken

It felt like Sherlock had been gone forever. In the time he’d been away, John had put Rosie to bed, pressed his face into a pillow to try and suppress his feelings, got up and made some tea, let his tea get cold because he was so distracted by what Sherlock had written, and got up and made tea again. John was just taking a sip from his mug when he heard Sherlock coming up the stairs.   
“Terribly sorry that took so long. I got into an argument with the owner of the closest shop, so I had to go to the next one down. It’s not my fault his wife is having an affair.” Sherlock muttered angrily, setting the bag of shopping down. John stood up, facing Sherlock. Sherlock instantly knew something was up. Body posture, shifty eyes...that little way John clenched his fist when he had something on his mind. There seemed to be an issue he wanted to discuss.   
“Sherlock” John started, before exhaling sharply. “Why did you never bloody say anything?”   
Sherlock frowned. “I’m sorry?”   
“All these years...all these bloody years I...” John ran his hand shakily through his hair. “You know, I gave up on you after you died”  
Sherlock was beyond confused. “John, you’re not being clear.”  
“I thought- when you came back I thought I’d moved on, you know” John was trembling. “But I suppose I made you feel like you just couldn’t tell me”  
“John-“ Sherlock furrowed his brow, stepping forwards. “What’s going on? What have I done?”   
To Sherlock’s utter surprise, John stepped forwards so they were close enough for him to put his arms around Sherlock. 

“Why did you never tell me you love me?” John whispered.

Sherlock’s eyes widened. Oh god. The notepad, John had seen the notepad. John had seen everything. John had seen Sherlock’s humanity shamelessly spread out onto paper and John...John was holding him.  
Sherlock didn’t move, afraid he’d put John off.   
“I didn’t know” Sherlock spoke softly, thinking very carefully about his choice of words. “I’ve never experienced love before.”   
John pulled away, keeping his arms close around Sherlock’s sides.   
“And you’re sure you’re...you know. In love. With me.” John was gazing up at Sherlock with that soft look that made Sherlock’s heart melt into a puddle of goo.   
Sherlock scrunched up his face, thinking hard.   
“Logically speaking, none of this makes sense” he started slowly. “The science behind it is lacking, and I only vaguely understand the concept o-“   
“Christ Sherlock, just say it” John interrupted, closing his eyes. “Please. Just say it.”   
Sherlock started down at the carpet, and then slowly, slowly managed to look up again.  
“John Watson” he began, and he could hear his heart thudding in his ears. 

“I love you”

John opened his eyes, moving to cup Sherlock’s cheek in one hand.   
“You have no idea how long I’ve wanted to do this for” he murmured, slowly leaning in to kiss Sherlock. Sherlock found himself stooping a little to meet John’s affection, but it was the best thing he’d ever felt. John Watson kissing him sparked some kind of feeling in him. It was raw, and loud, and bright. It wasn’t logical, it made no sense. Science could put no label on it, and gravity could not keep it down. Sherlock understood the way a star must feel when it’s exploding. Untamed, unchecked. The four letter word that had been playing on his mind all those years had manifested itself. He was in love.  
He was in love with John Watson. 

When they finally pulled away, Sherlock pressed his forehead against John’s for a moment, taking everything in, before finally breaking the silence.  
“Can we do that again?”  
“Oh god yes.”

Several kisses and years worth of repressed emotions coming out later, and John and Sherlock were cuddled on the sofa together. Sherlock was drilling John with questions.  
“How do you know you love me? What is it supposed to feel like? Am I feeling the right way?” Sherlock was rambling. John could see he was on track to being overwhelmed, so he gently interrupted him.   
“Sherlock, look. Love- it’s just a four letter word. That’s all there is to it. There’s no set definition for love or anything, you don’t have to feel a certain way or do a specific thing for it to be right, because there is no right.”   
Sherlock nodded slowly, leaning his head on John’s shoulder.   
“All that matters right now is that we’re together” John ran his hand through Sherlock’s hair. “And that we’re honest with each other.”  
Sherlock nodded.   
“Does that make us boyfriends then?”  
“Do you want us to be boyfriends?”  
“Absolutely” Sherlock responded without hesitation.   
“Me too” John smiled, leaning over to kiss Sherlock’s cheek. 

John fell asleep in Sherlock’s arms that night, in Sherlock’s bed. Nothing had ever felt so perfect or so right for either of them. Sherlock could hardly fall asleep he was so overwhelmed with emotion, but he feared waking John up if he moved, so he stayed put. Just because John Watson was his boyfriend now didn’t mean Sherlock was going to become all domesticated, because that would never feel right for him. It did, however, mean he’d show off more, because now he had someone to really show off for. He laughed quietly. John was going to absolutely hate him for it.   
Yes, as it turns out he was absolutely, totally head over heels in love with John Watson, but love is just a four letter word. 

Love was going to be what Sherlock and John made it.

**Notes for the Chapter:**

> Whew! Thank you all so much for reading this! I’ve never written a fan fiction with several chapters before, so this has really been a learning experience for me. Thank you so much for all reading and supporting this! Genuinely, I truly value every single piece of feedback I receive. Would you guys like to see more Johnlock in the future? Please let me know!  
> Cheru <3

**Author's Note:**

> Hello and thank you so much for reading this! My name is Cheru and my aim is to make people smile!  
> Tumblr: cherubuni  
> Instagram: cherubuni


End file.
